A liquid crystal display driven by vertical alignment (VA: Vertical Alignment) mode includes a liquid crystal layer that employs homeotropic alignment, in which liquid crystal molecules are aligned perpendicularly to a substrate. When no voltage is applied across the liquid crystal layer, no change occurs to a state of polarized light that transmits through the liquid crystal layer. Thus, it is possible to carry out normally black display by arranging a polarizing plate in crossed Nicols. This improves deepness of the black display, thereby attaining a large contrast. However, while a voltage is applied across the liquid crystal layer, the liquid crystal molecules fall towards a substrate surface. Hence, with liquid crystal cells of a single domain structure, directions in which the liquid crystal molecules fall become lopsided, thereby causing colors to appear differently, depending on a viewed direction.
Accordingly, a MVA (Multi-domain Vertical Alignment) mode has been developed, which allows sighting a same display upon viewing from various directions. With the MVA mode, a liquid crystal cell is divided into a plurality of domains within a plane of the liquid crystal cell by use of an alignment control structure such as a rib. Directions in which the liquid crystal molecules fall are changed between the domains by use of the alignment control structure and a fringe electric field (oblique electric field) at a time when a voltage is applied, so that a screen is displayed evenly towards multiple directions.
Moreover, a PVA (Patterned Vertical Alignment) mode is also accomplished; slits are formed above and below a liquid crystal layer to serve as an alignment control structure, so that a plurality of sub-pixels are arranged, and liquid crystal molecules are aligned orthogonally while no voltage is applied. This also has allowed improvement in the black display quality.
Furthermore, CPA (Continuous Pinwheel Alignment) mode has also been accomplished, which is a further development of the MVA mode; a rivet that projects out perpendicularly to the liquid crystal layer serves as the alignment control structure, so as to cause the liquid crystal molecules to be aligned in a radial manner upon applying a voltage. Unlike the MVA mode, in the CPA mode, the alignment control structure causes no interference at the time when no voltage is applied. Hence the CPA mode has excellent vertical alignment, and has particularly excellent black display quality.
FIG. 18 is a plan view of a panel of a liquid crystal display disclosed in Patent Literature 1, as one example of a liquid crystal display including a liquid crystal layer that is driven by the VA mode.
Gate bus lines 12, drain bus lines 14, and storage capacitor bus lines 18 are provided on a TFT substrate 2. Further, on the TFT substrate 2, pixels connected to the gate bus lines 12 and drain bus lines 14 via a TFT 20 are disposed thereon in a matrix state. Each of the pixels includes a pixel electrode 16, and data signals are written into each of the pixel electrodes 16 from the drain bus lines 14 via a drain electrode 21 and source electrode 22 of the TFT 20. Moreover, the pixel electrodes 16 are connected to storage capacitor electrodes 19. The storage capacitor electrodes 19 and storage capacitor bus lines 18 are aligned parallel with each other, to form a storage capacitance.
Further, at intersecting positions of the gate bus lines 12 and drain bus lines 14, and at intersecting positions of the storage capacitor bus lines 18 and drain bus lines 14, projections 40 that serve as alignment control structures are formed. The projections 40 are formed of resist or the like, and are shaped substantially round when the projection is seen from a direction perpendicular to the substrate surface.